PORT ANGELES — A Port Angeles man is expected to be arraigned Tuesday, July 8, on attempted murder and assault charges after police say he injected his 57-year-old, non-diabetic step-uncle with a potentially deadly dose of insulin.

Robbie Wayne Davis, 39, was charged Tuesday in Clallam County Superior Court with one count each of first-degree attempted premeditated murder and first-degree assault, both with an aggravated circumstance.

Port Angeles police allege that Davis injected Richard Haynes, who has Down syndrome, with insulin while Haynes was hospitalized June 15 at Olympic Medical Center.

Davis remained Tuesday in the county jail on $25,000 bail.

Police say that about an hour after Davis left Haynes in his hospital room at 9:18 p.m., a nurse found the 57-year-old to be dangerously hypoglycemic, with a blood-sugar level between 30 and 100 points lower than normal.

Haynes was treated with medication and is recovering, police said. They said he had been hospitalized for a different ailment.

OMC video surveillance footage shows that Davis had been the only visitor to Haynes’ hospital room between 8:43 p.m. and 9:18 p.m. that day, police said.

Davis lives with Haynes and other family members on North Baker Street in Port Angeles.

One of the family members is an insulin-dependent diabetic and so needles and insulin are in the home, police said.

The nurse who came to Haynes’ aid found three marks on his left elbow “that appeared to be consistent with needle marks,” according to the police report filed in the case.

Two doctors interviewed by police, however, were divided on whether the marks were made by a needle.

During the investigation, police found Haynes, who medical personnel said has the intellect of a 3-year-old, had been hospitalized for extreme hypoglycemia two times since December.

On April 4, county sheriff’s deputies investigated a report of Haynes being admitted to OMC for conditions related to hypoglycemia.

Sheriff’s Office investigators “suspected that a member of Haynes’ family had administered insulin to him,” according to the Port Angeles police report filed in the attempted murder case.

A detective “developed probable cause to believe that somebody in the household had administered insulin to Haynes; however, there was insufficient evidence to develop probable cause to show that any one person was responsible for injecting Haynes with insulin,” the report said.

Police said Haynes was also checked into OMC with blood sugar between 40 and 110 points lower than normal on Dec. 12.

A doctor told police that this “most certainly caused at least some degree of permanent brain damage,” the report said, adding that the investigation into that incident is pending.

Haynes’ sister-in-law, also his primary caregiver, told police he had been in relatively good health and had not had any medical difficulties until Davis moved into the home between one and two years ago.